Our environment is becoming increasingly contaminated both due to a variety of different natural phenomena and due to the introduction of man-made pollutants into the air and water by industrial nations around the globe. Common examples of man-made pollutants introduced into the air include airborne particulates produced by combustion in hydrocarbon-burning power plants, incinerators, industrial processes of various kinds like smelting operations, nitric and sulfuric acid plants, internal combustion engines, etc. For the most part, such pollutants comprise oxidation products of carbon, sulfur, nitrogen, lead, zinc, and other elements. For example, since coal includes traces of various impurities, including lead, zinc, silver, etc., when coal is burned the carbon in the coal as well as these impurities are oxidized. Finally, the sulfur oxides and nitrogen oxides produced from the combustion of fuels containing sulfur compounds and the combustion of fuels that contain nitrogen compounds form acids that contribute to acid rain, an increasingly significant environmental concern.
Many approaches have been developed to treating the combustion products of hydrocarbon-burning power plants, incinerators, industrial processes, internal combustion engines, etc. to control the introduction of airborne particulates from these sources. For example, coal-burning power plants often employ scrubbing processes that use calcium compounds that react with sulfur oxides to form gypsum. Unfortunately, the substantial amounts of waste products produced by such scrubbing processes present serious disposal problems. Where possible, low-sulfur coals are used in coal-burning power plants to reduce scrubbing requirements, but this increases the costs of power generation. Alternatively, sulfur oxide emissions are reduced by operating the plants at lower temperatures, but this leaves some of the heating value of the coal untapped.
Another approach to treating such emissions has been to use electrostatic precipitators to enhance the removal of particulates. In this approach various types of ionizers are used to create ions that attach themselves to the particulates. The resulting charged particulates are then collected as such in an electrostatic precipitator.
Unfortunately, the prior approaches to controlling the introduction of combustion-produced airborne particulates have met with one or more serious problems. For example, they have not been able to reduce emissions to acceptable levels, they have been inordinately expensive to build or operate, and they have been energy inefficient.
The present invention provides apparatus and methods for treating an air flow containing particulate combustion products to reduce them to elemental material and water. The apparatus and methods of the invention also provide means for removing the elemental material, leaving a cleansed and greatly improved air flow and making it possible to recover valuable elemental materials where desired. Finally, the present invention achieves all of these objectives in a highly energy-efficient manner.
Fullerenes are one of the valuable elemental materials that can be recovered using the apparatus and method of the present invention. Fullerenes are a very dear and industrially important form of carbon comprising a large closed-cage molecule made up of 60 or more sp2-hybridized carbon atoms, arranged in hexagons and pentagons. Currently, fullerenes are known in the form of spheriods (“buckminsterfullerene”) and cylindrical or torroidal shapes (“nanotubes”). Various complex and expensive processes are known for producing fullerenes. Because the processes are so complex, and the yields so low, the resulting product is very, very expensive. The present invention provides a far more efficient and inexpensive method for producing these materials.
Since the apparatus of the present invention operates on only a small amount of energy, when the apparatus is used to treat the emissions of a coal-operated power plant, carbon may be recovered from the plant's smokestack and repeatedly re-used to fuel combustion, greatly enhancing the efficiency of the power plant.
Finally, the present apparatus is also useful in reducing landfill requirements. For example, since the invention is so efficient in cleaning the air, it makes possible the use of incinerators which have been heretofore banned or discouraged because of the difficulty of effectively controlling the air pollution that they produce. Thus, many materials that otherwise would be incinerated have been land-filled, unnecessarily wasting substantial landfill area. If such materials could be burned in incinerators and treated in the present apparatus this would greatly reduce the volume of the remaining material (primarily the collected elemental material) which could then be land-filled, taking up substantially less landfill area. Furthermore, already buried landfill material may be mined, incinerated, treated in accordance with the present invention and returned to the landfill to greatly reduce the volume of the mined landfill, substantially extending the lifetime of the landfill.